One way of dealing with a well leaking oil is to drill a side track or lateral through which the oil can be diverted to block the top of the leaking well, thereby stopping the leakage. Thus, drilling a side track or lateral from the surface for colliding with the side of the leaking casing at a certain depth requires guidance of the drilling tool during the drilling process.
In addition, drilling a side track from an existing well in an oil field of several wells all having several side tracks also requires that the drill head can be controlled to prevent collision with other side tracks of the same or other wells.
Thus, there is a need for a navigation system for navigating the drill head into collision with a leaking casing or preventing collision with another side track or well.